The Nook does not use the Pearl screen, but rather the older version of the Visiplex epaper screens. My opinion of it when it first came out was that it was heavier than the other readers I'd seen, had a much shorter battery life (that LCD screen at the bottom sucks power), and a slow and buggy interface that was not intuitively obvious. In addition, Barnes & Noble designed it so that the niftier features, like cover flow on the LCD screen only worked if the content was purchased from Barnes & Noble. I freely admit that I like touchscreens, but I found it somewhat disconcerting to be touching a screen at the bottom of the reader to get a result higher up.
In fairness to the Nook, Barnes & Noble has released upgraded firmware since it first came out, so some of my software objections may be fixed by now. The weight and the battery life kept me from ever looking at it again.